CMake: allow to disable GSL
This fix should allow to not use GSL (e.g. when MKL is present), with -DGSL=OFF -DCMAKE_DISABLE_FIND_PACKAGE_GSL=ON
.
This fix should allow to not use GSL (e.g. when MKL is present), with -DGSL=OFF -DCMAKE_DISABLE_FIND_PACKAGE_GSL=ON
.